Wide-band wide-input efficiency-enhanced CMOS rectifier with self temperature and process compensation

We present in this paper the design of a wide-band wide-input efficiency-enhanced CMOS rectifier for inductively powered telemetric systems. The integrated gate controlled diode is developed for the rectifier to minimize the dropout voltage in the forward conducting path, while maintaining low reverse leakage flow. Besides, the new rectifier features an implicit temperature and process compensation mechanism, that effectively reduces the deviation in the output voltage by tracking the threshold drift in the main diode device. The rectifier is optimized for high output power in this design, but the technique can be easily implemented for micro energy harvesters where the input voltage/power is low. The rectifier is fabricated in AMS 0.35μm 4M/2P standard CMOS process with maximum threshold of |V_THP|=1.12V and V_THN=0.8V. With a 13.56MHz input at 5V amplitude and a load resistor of 1.8k, the rectifier achieves 84.4% voltage conversion efficiency and 82% power conversion efficiency. The performance remains essentially unchanged from 1MHz to 20MHz input frequency and slight variation from 1.5V to 5.5V input amplitude.